In capacitive dimension gauging, as, for example, represented by commonly assigned U.S. Pat. Nos. 3,706,919, 3,775,679 and 3,990,005, it is known that the typical capacitive output varies inversely with the physical dimension gauged. This is due to the mathematics of capacitive gauging. It is often desired to convert this inversely varying output signal into a signal which is directly proportional to the dimension being gauged and accordingly linearizing schemes as evidenced in the above, last identified patents have been developed. Such schemes typically operate by electronic analog or digital division circuitry and/or nonlinear circuits themselves such as breakpoint approximation networks.
The resulting signal directly proportional to the gauged dimension is, however, not entirely free of nonlinearities. While indeed this signal does vary with the dimension being gauged, the transfer function between the output signal and dimension is seldom a perfectly straight line as would be desired. The actual deviation from the straight line condition can be as much as several percent of the value being measured.